Chernova, Marina N., Andrew K. Stewart, Lianwei Jiang, David J. Friedman, Yune Z. Kunes, and Seth L. Alper. Structure-function relationships of AE2 regulation by Cai 2 -sensitive stimulators NH4 and hypertonicity. Am J Physiol Cell Physiol 284: C1235–C1246, 2003. First published January 15, 2003; 10.1152/ajpcell.00522.2002.—We showed previously that the nonerythroid anion exchanger AE2 and the ...

During early development, gamma-aminobutyric acid (GABA) depolarizes and excites neurons, contrary to its typical function in the mature nervous system. As a result, developing networks are hyperexcitable and experience a spontaneous network activity that is important for several aspects of development. GABA is depolarizing because chloride is accumulated beyond its passive distribution in thes...

To evaluate the role of cytoplasmic domains of membrane-spanning proteins in directing trafficking through the secretory pathway, we generated fluorescently tagged VSV G tsO45 with either the native G tail (G) or a cytoplasmic tail derived from the chicken AE1-4 anion exchanger (G(AE)). We previously showed that these two proteins progressed through the Golgi with distinct kinetics. To investig...

Human organic anion transporter 4 (hOAT4) is located at the apical membrane of proximal tubule cells and involved in renal secretion and reabsorption of endogenous substances as well as many drugs and xenobiotics. This study reevaluated the physiologic role, transport mode, and driving forces of hOAT4. 6-Carboxyfluorescein (6-CF) uptake into HEK293 cells that stably expressed hOAT4 was saturabl...

1. Introduction Functions and biochemical properties of several membrane transporter proteins from human erythrocyte, in particular, the glucose transporter (Glut1) and anion exchanger (AE1, also called Band 3) have been extensively characterized. Glut1 is a member of the mammalian facilitative glucose transporter family Glut1-13 (1,2). The 50-kDa integral membrane protein is expressed in all h...

One member of the OATP family of transporters, rat Oatp1, functions as an anion exchanger that is driven in part by the glutathione (GSH) electrochemical gradient, indicating that other OATP-related transporters may also be energized by this mechanism. The present study examined whether rat Oatp2 is also an anion exchanger, and, if so, whether it is energized by the GSH electrochemical gradient...

Bachmann, O., T. Sonnentag, W.-K. Siegel, G. Lamprecht, A. Weichert, M. Gregor, and U. Seidler. Different acid secretagogues activate different Na1/H1 exchanger isoforms in rabbit parietal cells. Am. J. Physiol. 275 (Gastrointest. Liver Physiol. 38): G1085–G1093, 1998.—Rabbit parietal cells express three Na1/H1 exchanger isoforms (NHE1, NHE2, and NHE4). We investigated the effects of carbachol,...

The anion exchanger Pendrin, which is encoded by SLC26A4 (human)/Slc26a4 (mouse) gene, is localized on the apical membrane of non-acid-secreting intercalated (IC) cells in the kidney cortical collecting duct (CCD). To examine its role in the mediation of bicarbonate secretion in vivo and the apical Cl(-)/HCO(3)(-) exchanger in the kidney CCD, mice with genetic deletion of pendrin were generated...

Hydrogen sulfide (H(2)S), an endogenous gaseous mediator, produces both vasorelaxation and vasoconstriction at different concentrations. We found in the present study that NaHS, an H(2)S donor, produced stronger vasorelaxant and weaker vasoconstrictive effects in HEPES solution compared with those achieved in Krebs solution. We further screened the buffer components and found that bicarbonate (...

PURPOSE Bicarbonate transport plays a role in aqueous humor (AH) secretion. The authors examined bicarbonate transport mechanisms and carbonic anhydrase (CA) in porcine nonpigmented ciliary epithelium (NPE). METHODS Cytoplasmic pH (pH(i)) was measured in cultured porcine NPE loaded with BCECF. Anion exchanger (AE), sodium bicarbonate cotransporter (NBC), and CA were examined by RT-PCR and imm...